Hole plugging method for printed circuit boards, and hole plugging device

ABSTRACT

A hole plugging method for a printed circuit board, a hole plugging device in accordance therewith and a manufacturing method in accordance therewith where a mask for selectively exposing a via hole, a through hole and a surface pattern of the printed circuit board is positioned on the board having the via hole and the through hole to electrically connect circuit patterns formed on the surface of the board and in the board and an insulating material is plugged in the via hole by abutting and pushing the material on the surface of the board. Therefore, the insulating material can be plugged smoothly without a void, the processing is simplified by plugging the insulating material just to the height of the circuit pattern in a space between the circuit patterns and accordingly, damage to the circuit pattern can be prevented.

[0001] The present application is a divisional of co-pending U.S. patentapplication Ser. No. 10/043,146 filed on Jan. 14, 2002 for whichpriority is claimed under 35 U.S.C. § 120. This application also claimspriority under 35 U.S.C. § 119(a) on Patent Application No. 31752/2001filed in Korea on Jun. 7, 2001 and Patent Application No. 51853/2001filed in Korea on Aug. 27, 2001. The entire contents of each of theseapplications are herein fully incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a hole plugging method forprinted circuit boards, a hole plugging device which carries out suchmethod and a manufacturing method in accordance, and particularly, to ahole plugging method for printed circuit board and to a hole pluggingdevice and a manufacturing method in accordance therewith which plugsholes in a printed circuit board with an insulating resin or solderresist by abutting a squeegee or doctor blade to an exposed hole using amask capable of exposing a certain portion of a board or plugs resin orsolder resist between circuit patterns with.

[0004] 2. Description of the Background Art

[0005] Recently, integrated circuits (IC) have become more densified byan increase in the degree of integration according to the development oftechnology. Accordingly, it is required that a printed circuit board formounting ICs become more densified.

[0006] For meeting this necessity, currently, the printed circuit boardis densified by fabricating a multi layer (printed circuit) board formedwith a plurality of layers. In the multi layer board 1, open throughholes 1 d and via blind holes 1 c may be form in the board wherein aconductive layer 1 e is coated in the holes 1 c and 1 d to electricallyinterconnect circuit patterns 1 a and 1 b of one or more an inner layersand/or the surface layers, with reference to FIG. 1A.

[0007] The through hole 1 d has a relatively large diameter than the viahole 1 c and is typically formed by employing a mechanical process suchas by drilling. However, the interval between the through holes 1 d cannot be narrowed beyond a certain spacing and there is thus a limitationin the densification degree of the board when the sizes of tools andavoidance of damage to the board 1 in the processing are taken intoconsideration.

[0008] Based on the above characteristics, in the case of forming a viahole 1 c with a small diameter by employing a chemical method such as byetching, the interval between adjacent via holes 1 c can be madenarrower than that between the through holes 1 d, and a circuit patterncan be formed at the portion adjacent the via hole 1 c and the upperside of the via hole 1 c, thus to achieve higher integration andminiaturization of the printed circuit board.

[0009] Such a via hole 1 c has a conductive layer 1 e and is coated witha solder resist using a screen printing process or a roller coatingprocess to protect the conductive layer 1 e from external impact and toprevent foreign materials from attaching to the conductive layer 1 e.

[0010] First, the conventional hole plugging method of the printedcircuit board using the screen printing process will be described withreference to FIGS. 1A and 1B.

[0011] The structure of the printed circuit board includes circuitpatterns (surface circuits patterns) 1 a positioned on both the upperand lower surfaces of the board 1 and circuit patterns (internalcircuits) 1 b positioned in the inner layers of the board.

[0012] On the board 1, a via holes 1 c is formed to electricallyinterconnect the surface circuit pattern 1 a and internal circuit 1 bthrough the conductive layer le, and the through hole 1 d is formed toelectrically interconnect both the upper and lower surface circuitpatterns 1 a through the conductive layer 1 e.

[0013] In the hole plugging method of the printed circuit board usingthe screen printing technique, the board 1 is positioned on a jig (notshown) and a screen 2 such as a mesh is positioned at the upper sidethereof at a certain distance.

[0014] Then, after coating solder resist (SR) on the upper surface ofthe screen 2, the solder resist (SR) is discharged through an opening 2a in the screen 2 by pushing a squeegee 3 in the direction of the arrowin the drawing and then is filled in the via hole 1 c and through hole 1d of the board 1.

[0015] In the above screen printing technique, the screen 2 is formed inthe form of a mesh by weaving a plurality of fine wires 2 b crossingeach other. The wire diameter of a #110 screen is approximately 0.08 mmand the wire diameter of a #600 screen is approximately 0.045 mm. Asshown in FIG. 1B, if that the diameter of the subminiature via hole is0.1 to 0.15 mm, in the portion where the fine wires intersect, part ofthe via hole 1 c is covered since the diameter of the conventional finewire 2 b is half that of the via hole 1 c.

[0016] Particularly, a considerable portion of the via hole 1 c wherethe fine wires 2 b cross each other is covered and accordingly, thesolder resist (SR) cannot be plugged sufficiently.

[0017] Also, the solder resist (SR) is coated in the space 1 f betweenthe surface circuit pattern 1 a and the screen 2 since the solder resistSR is coated by using the screen 2. However, removing the solder resistSR afterwards by an abrasive process to expose the surface circuitpattern 1 a is not easy since the solder resist SR is coated coveringthe surface circuit pattern 1 a completely and damages may result to thesurface circuit pattern 1 a in case of removing the solder resist SR byusing a brush and the like.

[0018] Second, the conventional hole plugging method of the printedcircuit board using the roller coating technique will be described withreference to FIGS. 2A and 2B.

[0019] In the hole plugging method using the roller coating aftersupplying the solder resist SR to an upper roller 4 a and lower roller 4b, the solder resist SR at the rollers 4 a and 4 b is transferred to theboard 1 and coated by passing the board 1 between rollers 4 a and 4 b atthe both side thereof.

[0020] In the conventional roller coating method, the solder resist SRis coated by putting the solder resist SR in a groove (not shown) formedon the circumferential surface of the rollers 4 a and 4 b, but in case aprojecting portion 5 with relatively small amount of solder resist SR isabutted to the via hole 1 c or blocks up the via hole 1 c, a sufficientamount of solder resist SR can not be plugged.

[0021] In the screen printing method, the solder resist SR is coated inthe via hole 1 c or the through hole 1 d of the board 1 by pushing thesolder resist SR coated on the screen 2 after putting the screen 2 onthe board 1. In the roller coating method, the solder resist SR on therollers 4 a and 4 b is flowed and coated on the via hole 1 c and thethrough hole 1 d of the board 1. Air bubbles remaining behind in thesolder resist SR are discharged due to the high heat when the integratedcircuit (not shown) is mounted, and accordingly the circumferentialcircuit patterns, solder resist and integrated circuit can be damagedeven though the solder resist SR is filled in the via hole 1 c and thethrough hole 1 d. Also, the coefficients of thermal expansion of theintegrated circuit and the board are different and accordingly, theboard can be damaged when high heat is generated in the integratedcircuit.

[0022] To solve the above problems, the present applicant had filed anearlier application for “A Method for Fabricating a Printed CircuitBoard using Vacuum” (Korea Patent Application No. 2000-19045) on Apr.11, 2000 and also an application for US Letters patent therefore, underU.S. patent application Ser. No. 09/832,122.

[0023] In the above fabrication method, the solder resist is coated onthe via hole of the board, and at the same time air in the via hole isdischarged to the outside and the solder resist is plugged in the viahole. The solder resist can be plugged in the via hole efficiently bycompletely removing the residual air bubbles in the via hole. However,there are disadvantages in the cost and the manufacturing time, in thata vacuum device must be equipped and repeated operation of exposureunder the vacuum condition and plugging operations are needed thus toreduce productivity.

SUMMARY OF THE INVENTION

[0024] Therefore, an object of the present invention is to provide ahole plugging method for printed circuit boards and a hole pluggingdevice in accordance therewith, capable of smoothly plugging a solderresist insulating material in a via hole formed to electrically connecta circuit pattern formed on the surface of the board and a circuitpattern formed in the board, or in a through hole formed to electricallyconnect the circuit patterns on the both side surfaces of the board.

[0025] Another object of the present invention is to provide a holeplugging method for printed circuit boards and a hole plugging device inaccordance therewith capable of plugging a resin insulating material bycoating the resin in spaces between the circuit patterns just to theheight of the circuit patterns and at the same time, minimizing theamount of insulating material coated on the circuit pattern.

[0026] Still another object of the present invention is to provide ahole plugging method for printed circuit boards and a hole pluggingdevice in accordance therewith capable of preventing bubbles fromremaining behind in the insulating material plugged in the spacesbetween via holes, through holes or circuit patterns on the board.

[0027] Still another object of the invention is to provide a holeplugging method for printed circuit boards and a hole plugging device inaccordance therewith capable of preventing an integrated circuit on theboard from being damaged by restraining the formation of residualbubbles in the insulating material in the spaces between the via holes,through holes or circuit patterns on the board sufficiently.

[0028] To achieve these and other advantages and in accordance with thepurpose of the present invention, as embodied and broadly describedherein, there is provided a hole plugging method for printed circuitboards in which an insulating material is plugged in a via hole byabutting a squeegee for plugging an insulating material in the via holedirectly to a surface of a board where the via hole is formed toelectrically connect a circuit pattern formed on the surface of theboard and a circuit pattern formed in the board.

[0029] Also, to achieve the above object, there is provided a holeplugging method for printed circuit boards, wherein an insulatingmaterial is plugged in exposed via holes by positioning a mask forselectively exposing the via holes on the board where the via hole isformed to connect a circuit pattern formed on the surface of the boardand a circuit pattern formed in the board electrically.

[0030] Also, to achieve the above object, the hole plugging method forthe printed circuit boards in accordance with the present inventionpushes and plugs the insulating material into the spaces between thecircuit patterns by abutting the squeegee for plugging the insulatingmaterial in the spaces between the circuit patterns formed on thesurface of the board to the surface of the board and the circuitpatterns.

[0031] Also, to achieve the above object, in the hole plugging methodfor the printed circuit boards, a mask for selectively exposing theinsulating material in the spaces between the circuit patterns to plugthe insulating material in the spaces among the circuit patterns formedon the surface of the board is positioned on the board and theinsulating material is plugged only in the spaces between the exposedcircuit patterns.

[0032] To achieve the above object, the hole plugging method for theprinted circuit boards in accordance with the present invention includesthe steps of providing the mask exposing the via hole and coveringanother portion on the board, the board having the via hole forconnecting the circuit pattern to connect the circuit pattern formed onthe surface of the board and the circuit pattern formed in the boardelectrically, positioning the mask on the board and plugging theinsulating material in the via hole or in the spaces between the surfacecircuit patterns by coating the insulating material on the portion ofthe board exposed by the mask.

[0033] Also, to achieve the above object, the hole plugging method forthe printed circuit boards in accordance with the present inventionincludes the steps of providing the mask exposing the via hole andcovering another portion on the board, the board having the via hole forelectrically connecting the circuit pattern formed on the surface of theboard and the circuit pattern formed in the board and the through holefor electrically connecting the circuit patterns of the both sidesurfaces, positioning the mask on the board and plugging the insulatingmaterial in the via hole by coating the insulating material on theportion of the board exposed by the mask.

[0034] To achieve the above object, the hole plugging device for theprinted circuit boards in accordance with the present invention includesa mask positioned on the board where the via hole is formed to connectthe circuit pattern formed on the surface of the board and the circuitpattern formed in the board electrically, and a pressing means forplugging the insulating material in the via hole by coating theinsulating material on the surface of the board exposed by the mask.

[0035] On the other hand, to achieve the above object, in the holeplugging method for the printed circuit boards in accordance with thepresent invention, solder resist or insulating resin is filled in thespaces between surface side circuit patterns by moving the squeegeeunder the condition of being abutted on the upper surface of the circuitpattern on the surface of the printed circuit board, the board having aplurality of circuit patterns formed thereon and formed in the board anda hole for electrically connecting the circuit pattern formed on thesurface of the board and the circuit pattern formed in the board or forconnecting the circuit patterns on the both side surfaces and by movingthe squeegee being abutted to the surface of the printed circuit board.

[0036] The foregoing and other objects, features, aspects and advantagesof the present invention will become more apparent from the followingdetailed description of the present invention when taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this specification, illustrate embodiments of theinvention and together with the description serve to explain theprinciples of the invention.

[0038] In the drawings:

[0039]FIG. 1A is a cross-sectional view showing a hole plugging methodfor printed circuit boards using a conventional screen printing method;

[0040]FIG. 1B is a plan view briefly showing a hole plugging process forprinted circuit boards using the conventional screen printing method;

[0041]FIG. 2A is a cross-sectional view briefly showing the holeplugging for printed circuit boards using a conventional roller coatingmethod;

[0042]FIG. 2B is an enlarged cross-sectional view showing the holeplugging process for the printed circuit boards using the conventionalroller coating method;

[0043]FIG. 3 is a perspective view showing a hole plugging device forprinted circuit boards according to an embodiment of the presentinvention;

[0044]FIG. 4 is a cross-sectional view showing the hole plugging deviceand method for printed circuit boards according to the embodiment of thepresent invention;

[0045]FIG. 5 is a detail view showing a state where a hole is plugged ina printed circuit board according to the embodiment of the presentinvention;

[0046]FIG. 6 is a cross-sectional view showing the hole plugging methodfor printed circuit boards according to another embodiment of thepresent invention; and

[0047]FIG. 7 is a cross-sectional view showing the hole plugging methodfor printed circuit boards according to another embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] Reference will now be made in detail to the preferred embodimentsof the present invention, examples of which are illustrated in theaccompanying drawings.

[0049]FIG. 3 is a perspective view showing a hole plugging device forprinted circuit boards according to an embodiment of the presentinvention, FIG. 4 is a cross-sectional view showing the hole pluggingdevice and method for printed circuit boards according to the embodimentof the present invention and FIG. 5 is a detail view showing a statewhere a hole is plugged in a printed circuit board according to theembodiment of the present invention.

[0050] Firstly, the printed circuit board includes a surface circuitpattern 1 a and internal circuit conductors 1 b are formed on and in aboard 1 respectively, a via hole 1 c formed to electrically connect thesurface circuit pattern 1 a and the internal circuit pattern 1 b by aconductive layer 1 e, and a through hole 1 d formed to connect the bothside surface circuit patterns 1 a by the conductive layer 1 e.

[0051] The hole plugging device for a printed circuit board inaccordance with the present invention includes a mask 10 wherein aopening portion 11 is formed to selectively expose the via holes 1 c,through holes 1 d and the surface circuit patterns 1 a under thecondition of being positioned on the board 1 and a squeegee 20 whichserves as a pressing implement, by being directly abutted on the exposedpart of the board 1 exposed by the mask 10 to coat a resin or solderresist SR thereon, which are insulating materials.

[0052] It is desirable that the mask 10 is made of a metal materialhaving a certain extent of tension to correspond to stress generatedwhen the squeegee 20 is given pressure, but the mask can be formed witha mixed material of a fibrous material and a resinous material or of afilm type member.

[0053] Also, the mask 10 includes an opening portion or portions 11formed by cutting away portions thereof corresponding in location toareas to be exposed on the board 1 among the via holes 1 c and thethrough holes 1 d of the board 1, as with a laser and the like, and amasking portion 12 which does not expose the board 1.

[0054] The process of plugging resin or solder resist in the via holesand the through holes of the printed circuit board using the holeplugging device in accordance with the present invention will bedescribed as follows.

[0055] As shown in FIG. 4, in case the board has a circuit pattern as afour layer structure by independently forming the surface circuitpatterns 1 a on the both upper and lower surfaces of the board 1 andforming the internal circuits 1 b in the board 1 as a two layerstructure, the surface of the conductive layer 1 e is coated with resinor solder resist to protect the conductive layer 1 e since the via hole1 c and the through hole 1 d have the conductive layers 1 e which aremetal layers to conduct electricity.

[0056] The mask 10 is positioned by having the opening portion 11 in themask 10 correspond to the via hole 1 c to expose the via hole 1 c of theboard 1.

[0057] The element designated by reference numeral 6 and indicated withdotted lines in FIG. 3 is a circuit area of the board 1 corresponding tothe opening portion 11. Therefore, the via hole 1 c of the circuit area6 is exposed by the opening portion 11 and the other areas on the board1 are masked by the masking portion 12.

[0058] Next, when the squeegee 20 is lowered and the squeegee is abuttedon the mask 10 and if the squeegee is pressed down more, the squeegee 20is abutted on the mask and through opening 11 as the end of the blade ofthe squeegee is bent.

[0059] The resin or solder resist SR is plugged in the via hole 1 c bymoving the squeegee 20 in the direction of the arrow as shown in FIG. 4.

[0060] Namely, as the lower end of the blade of squeegee 20 passes overthe surface of the masking portion 12 of the mask 10, the squeegee 20pushes the resin or solder resist SR positioned on the surface. Then, asthe squeegee 20 is progressed while being abutted on the upper surfaceof the board 1 by positioned at the opening portion 11 of the mask 10,the squeegee plugs the resin or resister SR into the via hole 1 c bypushing the resin or solder resist SR while being positioned on theboard 1.

[0061] At this time, as shown in FIG. 5, the resin or solder resist SRis consequently filled from the left side to right side of the via hole1 c by the resultant force F of vertical component force F_(y) andhorizontal component force F_(x) of the squeegee 20, directed in thedownward direction since the squeegee 20 is abutted on the surface ofthe board 1 under the condition that the end portion of the bladethereof is bent. The air in the via hole 1 c is displaced as thesqueegee forcefully pushes the resin or solder resist SR and is removedas shown in the drawing.

[0062] Next, after the plugging processing of the resin or solder resistSR into the via hole 1 c, the mask 10 is removed and the resin or solderresist SR is plugged into the through holes 1 d. As described above,because the through holes 1 d have a larger diameter than the via holes1 c, accordingly the resin or solder resist SR can be smoothly pluggedinto the through holes using the conventional above described screenprinting method or roller coating method.

[0063] Then, light is irradiated onto the board 1 under the conditionthat the mask 10 capable of exposing the via hole 1 c and the throughhole 1 d is positioned on the upper surface of the board 1 where theresin or solder resist SR is coated and thereby only the exposed portionof the resin or solder resist SR is hardened. The mask 10 is taken awayand the printed circuit board is completed by performing a series ofpost operations for grinding the board 1 with a grinder (not shown)after developing and removing the solder resist SR which is nothardened.

[0064] On the other hand, the through hole 1 d can also be filled withthe resin or solder resist SR by using a mask (not shown) manufacturedto expose only the through hole 1 d, as in the earlier procedureexposing only the via hole 1 c. At this time, it is desirable that theresin or solder resist SR is plugged by abutting the squeegee 20 on theupper surface of the board 1 pushing the resin or solder resist SR.

[0065] The screen printing method of positioning a wire woven mesh sievebetween the squeegee 20 and the board 1 to plugging holes by positioningthe screen having the resin or solder resist or the roller coatingmethod for passing the board between rollers covered with resin orsolder resist can also be used for plugging the through holes.

[0066] In case of additionally using the mask 10 capable of exposing thethrough hole 1, wastage of the resin or solder resist SR in massproduction of the printed circuit board can be prevented by blocking theresin or solder resist SR using the mask at the portion of the boardwhere the resin or solder resist SR is not needed to be coated such asin between the via hole 1 c and the through hole 1 d.

[0067] The hole plugging method of the printed circuit board inaccordance with the present invention will be described with referenceto FIGS. 6 and 7.

[0068] In the above embodiment, the resin or solder resist was filled inthe via hole or through hole using the squeegee one time but in thefollowing embodiment, the resin or solder resist can be sufficientlyplugged in the hole by moving the squeegee at least two times, in casethe resin or solder resist is not completely plugged in the hole due tothe via hole having a small diameter and a large depth, even though thesqueegee is moved one time.

[0069] Namely, as shown in FIG. 6, after positioning the mask 10 fordividing the areas where the resin or solder resist SR is to be coatedor not coated on the printed circuit board 1, when the squeegee 20 isdirectly abutted onto the surface of the printed circuit board 1 as thesqueegee 20 is bent a little by virtue of its elasticity and is therebyabutted directly on the upper surface of the surface side circuitpattern 1 a.

[0070] Then, as shown in FIG. 6, when a first plugging step is performedby moving the squeegee 20 in the direction of the arrow after coatingthe resin or solder resist SR on the surface of the printed circuitboard 1, the resin or solder resist SR is coated and filled in thespaces between the surface side circuit patterns 1 a.

[0071] At this time, as the squeegee 20 is moved in constant abuttedrelation to the circuit patterns 1 a, the height of the coated resin orsolder resist SR plugged in the spaces 1 f between surface side circuitpattern 1 a is not protruded higher than the upper surface of thecircuit pattern. At this time, in case the entrance side diameter of thevia hole 1 c is small and the depth is about three times or more deeperthan the thickness of the surface side circuit pattern 1 a, the resin orsolder resist SR may not be sufficiently plugged in the via hole 1 c,and only about a half of the hole depth is plugged as shown in FIG. 6.

[0072] Later, as shown in FIG. 7, after re-positioning the squeegee 20back to the original position, the squeegee 20 is moved to the positionas in the first plugging step or moved in the opposite direction to thatof the first plugging step and the resin or solder resist SR iscompletely plugged in the via hole 1 c by coating the resin or solderresist one more time.

[0073] Then, after removing the mask 10, the resin or solder resist SRis plugged in the through hole 1 d as done conventionally, or the resinor solder resist SR is additionally coated on the upper portion of thesurface side circuit pattern 1 a and the via hole 1 c at the same timeas the resin or solder resist SR is plugged in the through hole 1 d toprotect the exposed circuit pattern 1 c. Then, drying and grindingprocesses are performed.

[0074] On the other hand, in the step of plugging the via hole operatedin two steps, a step of removing air bubbles contained in the resin orsolder resist by exposing the printed circuit board under a vacuumcondition in the middle of each of the plugging steps can be performedadditionally.

[0075] In still another embodiment of the present invention, the resinor solder resist SR can be plugged in the through hole after pluggingthe resin or solder resist in the via hole as in the above embodiment,but the resin or resister SR can be plugged later in the via hole afterplugging the resin or solder resist in the through hole.

[0076] Namely, the resin or resister is plugged in the through holeusing a silk screen under the condition of exposing the circumferentialthrough hole after masking the via hole formed at the center portion ofthe printed circuit board and then the resin or solder resist can beplugged without additional masking after removing the mask.

[0077] Here, since the squeegee is not abutted on the surface of theprinted circuit board in plugging in the through hole, the resin orsolder resist is risen around the hole convexly. It is desirable thatthe resin or solder resist is formed as a flat surface through aflattening processing performed before or after plugging the via hole.

[0078] Since the resin or solder resist can be plugged in the via holeor the through hole using the squeegee directly abutted to the board,the resin or solder resist can be plugged in each hole sufficiently andresidual air bubbles can be restrained without performing complicatedprocessing such as the vacuum process.

[0079] Therefore, damage to the integrated circuit and printed circuitboard caused by the air bubbles in mounting or operating the integratedcircuit can be prevented and accordingly, reliability can be improvedand manufacturing time of the printed circuit board can be reduced, thusto improve productivity.

[0080] Particularly, in case the resin or solder resist is coated on thevia hole with a small diameter using the screen printing method or theroller coating method, the resin or solder resist is not sufficientlyfilled since the via hole is covered by the thickness of the screen orthe protruded portion of the roller, but in the present invention, theresin or solder resist can be sufficiently filled in each via hole sincethe resin or solder resist is plugged by directly abutting the squeegeeon the board.

[0081] Also, air in the resin or solder resist can be prevented fromremaining behind in the hole and the hole and the space in between thecircuit patterns by a processing can be plugged at the same time sincethe resin or solder resist is coated by fixedly-abutting the squeegee tothe printed circuit board.

[0082] Also, the width and interval of the printed circuit board inaccordance with the present invention can be precisely controlled byperforming two dimensional gold plating to perform gold plating only onthe upper side in plating gold on the pad terminals of the circuitpattern in the wire bonding processing for connecting the circuitpattern of the chip and the printed circuit board by wires in thepackaging operation to mount the chip.

[0083] In addition, in each embodiment of the present invention,although an insulating material to be plugged was described as limitedto the resin or solder resist SR, the descriptions above are justexamples and general epoxy resin and solder paste can be used as theinsulating material and more generally, materials having viscoelasticityand commonly used in manufacturing the printed circuit board can beused.

[0084] As described above, the hole plugging method for the printedcircuit boards, and the hole plugging device in accordance therewith caneasily plug the insulating material in holes with small diameters and inadvance prevent air bubbles from remaining behind in the pluggingprocess by plugging the insulating material in the via hole or throughhole by abutting the squeegee on the exposed portion after positioningthe mask capable of selectively exposing the portion where theinsulating material is to be coated on the board having the via hole andthe through hole on the board, thus to prevent damage to the integratedcircuit and the board caused by the air bubbles in mounting or operatingthe integrated circuit.

[0085] Also, other portions other than the circumference of the via holeor the through hole are not coated by the resin or solder resist whichis an insulating material and accordingly, waste of the insulatingmaterial can be prevented in mass production.

[0086] In case the grinding processing is performed to flatten thesurface of the board, since the resin or solder resist SR is not coatedat the upper surface of the surface circuit pattern 1 a or the amount orcoated thickness is small, the grinding process is eased and damage tothe surface circuit pattern 1 a caused by the grinding processing can beminimized.

[0087] Also, the present invention can enable forming the width andinterval precisely by performing two dimensional gold plating by whichthe upper surface of the pad is plated by gold when gold plating of thepad terminal in the circuit pattern is performed.

[0088] As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalence of such metes and bounds are therefore intendedto be embraced by the appended claims.

What is claimed is:
 1. A plugging method for a printed circuit boardhaving a plurality of first circuit patterns formed on a surface of theboard, a plurality of second circuit patterns formed in the board,comprising the steps of: filling a solder resist or resin in spacesbetween the first circuit patterns; grinding the surface of the board;and performing a two dimensional plating on an upper surface of thefirst pattern.
 2. The method of claim 1, wherein the two dimensionalplating is a gold plating.
 3. A method for manufacturing a printedcircuit board having a plurality of circuit patterns formed on a surfaceof the board and formed in the board and a plurality of holes forelectrically connecting the circuit patterns, comprising the steps of:filling a solder resist or resin in spaces between the circuit patternsformed on the surface of the board; grinding the surface of the boardand exposing an upper surface of the circuit patterns formed on thesurface of the board; and performing a two dimensional plating on theexposed upper surface of the circuit pattern formed on the surface ofthe board.
 4. The method of claim 3, wherein the two dimensional platingis a gold plating.
 5. The method of claim 1, wherein the solder resistor insulating resin is plugged into the hole by moving the squeegeeunder the condition of being abutted directly on the upper surface ofthe hole.
 6. The method of claim 1, wherein the step of filling thesolder resister or resin comprises; a first step of plugging the solderresist or insulating resin in one portion of the hole by moving thesqueegee under the condition of being abutted on the upper surface ofthe hole; and a second step of completely plugging the solder resist orinsulating resin in the whole portion of the hole by moving the squeegeeunder the condition of being abutted on the upper surface of the hole.7. The method of claim 6, wherein in the second plugging step the solderresist or insulating resin is plugged in the hole by moving the squeegeein the opposite direction to the moving direction of the squeegee in thefirst plugging step.
 8. The method of claim 6, wherein in the secondplugging step the solder resist or insulating resin is plugged in thehole by moving the squeegee in the same direction to the movingdirection of the squeegee in the first plugging step.
 9. The method ofclaim 1, wherein the solder resist or insulating resin is coated only onan area exposed by a mask for selectively exposing the plurality ofcircuit patterns formed on the printed circuit board at a predeterminedinterval or on the hole.
 10. The method of claim 1, wherein the solderresist or insulating resin filled in the spaces among the surface sidecircuit patterns is filled to the same height as the upper surface ofthe circuit patterns.
 11. The method of claim 3, wherein the solderresist or insulating resin is plugged into the hole by moving thesqueegee under the condition of being abutted directly on the uppersurface of the hole.
 12. The method of claim 3, wherein the step offilling the solder resister or resin comprises; a first step of pluggingthe solder resist or insulating resin in one portion of the hole bymoving the squeegee under the condition of being abutted on the uppersurface of the hole; and a second step of completely plugging the solderresist or insulating resin in the whole portion of the hole by movingthe squeegee under the condition of being abutted on the upper surfaceof the hole.
 13. The method of claim 12, wherein in the second pluggingstep the solder resist or insulating resin is plugged in the hole bymoving the squeegee in the opposite direction to the moving direction ofthe squeegee in the first plugging step.
 14. The method of claim 12,wherein in the second plugging step the solder resist or insulatingresin is plugged in the hole by moving the squeegee in the samedirection to the moving direction of the squeegee in the first pluggingstep.
 15. The method of claim 3, wherein the solder resist or insulatingresin is coated only on an area exposed by a mask for selectivelyexposing the plurality of circuit patterns formed on the printed circuitboard at a predetermined interval or on the hole.
 16. The method ofclaim 3, wherein the solder resist or insulating resin filled in thespaces among the surface side circuit patterns is filled to the sameheight as the upper surface of the circuit patterns.